sedimentary

Rounded quartz-rich river pebble

Lithic clast, likely quartzite or fine-grained sandstone

AI-generated identification · may be incorrect

Pale pinkish-gray, fine-grained, matte to weakly silky luster, with no visible crystals or cleavage; likely Mohs hardness 6–7 if quartzite, or 5–6 if sandstone. Its smooth oval shape reflects water abrasion rather than crystal form.

Identified August 30, 2026More sedimentary →

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Physical properties

Formation & geological history

A pre-existing quartz-rich rock was weathered, transported, and rounded in a stream or beach environment; the original rock may be Precambrian to younger, but the pebble’s depositional age cannot be determined visually.

Uses & applications

Typically used as a decorative pebble, landscaping stone, craft or tumbled-stone material; little jewelry value unless unusually attractive or proven to be quartzite from a notable locality.

Geological facts

The surface shape records abrasion during transport, while the pink coloration may come from iron oxides or minor feldspar. A streak, acid, and hardness test can distinguish sandstone from quartzite.

Field identification & locations

Common in riverbeds, beaches, gravel deposits, and glacial sediments worldwide. Quartzite resists scratching by steel and shows fused quartz grains; sandstone is more porous and may shed grains or absorb water.